The security field encompasses not only personalized documents such as passports, driving licenses, identity cards (ID cards) and admission documents such as visa's and entry tickets, but also the authentification and identification of goods to avoid counterfeiting, tampering and fraud such as lottery tickets, share certificates, transaction documents, labels on luggage and the packaging of pharmaceuticals and high value products in general.
The term “identity card” encompasses cards requiring bearer identification and range from national identity cards to establish the national identity of their civilians to cards involved in the electronic transfer of money such as bank cards, pay cards, credit cards and shopping cards to security cards authorizing access to the bearer of the card to particular areas such as a company (employee ID card), the military, a public service, the safe deposit departments of banks, etc. to social security cards to membership cards of clubs and societies.
ID cards usually contain information referring both to the authority issuing the card on the one hand and to the owner of the card on the other. The first type of information may be general information such as a name and/or logo of the issuing authority, or security marks, such as a watermark and security print, e.g. a repeating monochrome pattern or a gradually changing colour pattern which are difficult to counterfeit. The second type includes e.g. the unique card number, personal data such as a birth day, a photo of the owner, and a signature. The card can further contain hidden information and therefore contain a magnetic strip or an electronic chip (“smart cards”).
A large set of ID cards are usually prepared on a large web or sheet by a step and repeat process, after which the web or sheet is cut into multiple items with the appropriate dimensions each representing a personal ID card. Smart cards and ID cards have now the standardized dimensions of 85.6 mm×54.0 mm×0.76 mm.
Normally, the card is protected by a plastic sheet material for example by lamination of the card to a plastic sheet or, as is usually the case, by lamination between two plastic sheets.
In view of their widespread uses, particularly in commercial transactions such as cashing cheques, credit purchases etc., it is important that the person relying on the ID card to identify the bearer have maximum assurance that the ID card has not been altered and/or that the ID card is not a counterfeit.
The art's response to the counterfeiting problem has involved the integration of “verification features” with ID cards to evidence their authenticity. The best known of these “verification features” involve signatures such as the signature of the one authorized to issue the ID card or the signature of the bearer. Other “verification features” have included the use of watermarks, fluorescent materials, validation patterns or markings and polarizing stripes. These “verification features” are integrated into ID cards in various ways and they may be visible or invisible in the finished card. If invisible, they can be detected by viewing the feature under conditions which render it visible. Details relating to the use of “verification features” in ID cards can be found in U.S. Pat. Nos. 2,984,030, 3,279,826; 3,332,775, 3,414,998, 3,675,948, 3,827,726 and 3,961,956.
One method of realizing information in a multicoloured form, e.g. as an image or pattern, is the use of a dye diffusion transfer imaging system in which dye(s) are made to diffuse in pattern-wise distribution. All dye diffusion transfer imaging systems are based on the same principle of modifying the solubility of the dyes as a function of the amount of photographic silver halide developed. In commonly known dye diffusion transfer imaging processes the dye-providing substances are either initially mobile in alkaline aqueous media and become immobilized during processing, or initially immobile and become mobilized during processing. A survey of such processes has been given by C. C. Van de Sande in Angew. Chem.-Int. Ed. Engl. 22 (1983) no. 3, 191-209. More details on such processes and on dye-providing substances can be found in the literature cited therein and in DE-A Nos. 1,095,115; 1,930,215; 1,772,929; 2,242,762; 2,505,248; 2,543,902; 2,645,656; and the Research Disclosures Nos. 15,157 (November 1976) and 15,654 (April 1977).
EP-A 0 250 658 in claim 1 discloses an image receiving material suitable for image production by dye diffusion transfer processing controlled by the development of (an) image-wise exposed silver halide emulsion layer(s), wherein the support of said material is a resin support coated with an image receiving layer containing gelatin in admixture with a cationic polymeric mordant containing glycidyl groups that can react with active hydrogen atoms of gelatin, characterized in that the support is substantially consisting of a vinyl chloride polymer and the image receiving layer coated thereon has a weight ratio of said polymeric mordant to gelatin from 25:1 to 2.5:1, the gelatin being present at a coverage of at least 0.1 g per m2.
U.S. Pat. No. 4,820,608 discloses an image receptor element for dye diffusion transfer imaging processes comprising a support and an image-receiving layer incorporating a hydrophilic colloid, a non-polymeric phosphonium mordanting agent comprising at least one long chain hydrocarbon group and capable of fixing acid image dyes transferred to said image-receiving layer by diffusion, and a polymer comprising free acid groups, wherein said polymer is a copolymer latex comprising free weak acid groups and said image-receiving layer also comprises at least one heterocyclic compound corresponding to one of the following general formulae I, II, and III:
wherein: Y represents the non-metallic atoms needed to complete a saturated or unsaturated 5- or 6-membered heterocyclic nucleus, which may carry a fused-on aromatic ring system, and M represents hydrogen, an alkali metal atom, a quaternary ammonium group, or a negative charge forming an inner salt with a quaternized nitrogen atom of the heterocyclic compound.
The term “silver halide diffusion processes” refers to all black and white image-forming processes in which a positive is formed by diffusion reversal. The principles of the silver complex diffusion transfer reversal process, hereinafter called DTR process, have been described e.g. in U.S. Pat. No. 2,352,014 and in the book “Photographic Silver Halide Diffusion Processes” by André Rott and Edith Weyde, The Focal Press, London and New York, (1972). In the DTR process non developed silver halide of an information wise exposed photographic silver halide emulsion layer material is transformed with a so called silver halide solvent into soluble silver complex compounds which are allowed to diffuse into an image receiving element and are reduced therein with a developing agent, generally in the presence of physical development nuclei, to form a silver image having reversed image density values (“DTR image”) with respect to the black silver image obtained in the exposed areas of the photographic material.
U.S. Pat. No. 4,278,756 discloses a negative silver diffusion transfer process for making a reflective electrically non-conducting data storage medium from a photosensitive silver-halide emulsion comprising, defining at least one recording field in a photosensitive silver-halide emulsion, forming an area-wise surface latent image layer of silver precipitating nuclei by means of contacting the recording field of the photosensitive silver-halide emulsion with a fogging agent, said layer having a maximum nuclei volume concentration at one surface of the emulsion and a gradient in the depth-wise direction of decreasing concentration, contacting said photosensitive silver-halide emulsion with a reagent comprising a weak silver-halide developing agent for chemical development of said surface latent image layer of silver precipitating nuclei and a rapid-acting, silver-halide complexing solvent for reacting with unexposed and undeveloped silver halide to form soluble silver ion complexes which are transported by diffusion transfer to said chemically developed silver precipitating nuclei where silver of said silver ion complexes is precipitated and adsorbed on said chemically developed nuclei in the presence of said developing agent acting as a reducing agent, thereby forming a reflective, electrically non-conducting layer of aggregated and individual silver particles in the recording fields, the activity of solvent permitting chemical development of said surface latent image by the weak developing agent while simultaneously all of the undeveloped and unexposed silver halide is dissolved by the complexing agent.
U.S. Pat. No. 6,645,280 discloses an ink composition comprising a slow evaporating solvent and a translucentizing agent, wherein the ink composition is free or substantially free of colorants and is suitable for use in ink jet printing on paper substrates, and the slow evaporating solvent is present in an amount of from about 15% by weight to about 70% by weight of the ink composition, the translucentizing agent making the paper less opaque, and thus forming a visible image on the paper when viewed under light and typically, the translucentizing agent has a refractive index of from about 1.3 (±0.05) to about 1.7, and preferably from about 1.4 to about 1.6, at 20° C.
U.S. Pat. No. 6,358,596 discloses a cellulosic substrate having at least one transparentized portion formed therein, wherein said cellulosic substrate defines first and second major faces; said transparentized portion comprises a transparentizing composition applied to said cellulosic substrate in a predetermined pattern so as to define a graphical image having a relative transparency selected so as to define an area of increased transparency in said substrate; said area of increased transparency resembles a graphical watermark and defines a degree of transparency that excludes the degree of transparency defined by a transparent window; said transparentizing composition comprises a transparentizing agent and a security agent. The radiation curable transparentizing composition disclosed in U.S. Pat. No. 6,358,596 comprises at least one monomer selected from the group consisting of acrylate or methacrylate esters of polyhydroxy polyethers made from polyhydric alcohols (polyols) starting materials (compounds of Formula I) and/or acrylate or methacrylate esters of polyhydroxy polyethers made from primary or secondary amine starting materials (compounds of Formula II).
EP-A 1 362 710 discloses a method for producing a tamper proof carrier of information, said method comprising the following steps, in order: (1) providing a two-layer assemblage comprising (i) a rigid sheet or web support, and (ii) a porous opaque ink receiving layer comprising a pigment and a binder whereby either the surface of said support, or the surface of said opaque layer carries a first set of printed information, (2) printing a second set of information, different from said first set, onto said porous opaque ink receiving layer by means of ink jet printing, (3) covering totally, partially, or pattern-wise the thus obtained assemblage with a UV-curable lacquer composition, by means of coating, printing, spraying or jetting, whereby on penetration of the lacquer in said porous opaque ink receiving layer this layer becomes substantially transparent, (4) curing said lacquer composition by means of an overall UV exposure, thereby improving the adhesion between said support and said ink receiving layer, and the cohesive strength of said ink receiving layer.
EP-A 1 398 175 discloses four different embodiments of an information carrier. In the first embodiment the information carrier comprising: a rigid sheet or web support; an opaque porous receiving layer capable of being rendered substantially transparent by penetration by a lacquer, said receiving layer containing a pigment and a binder; an image provided onto and/or in said receiving layer; a cured pattern of a varnish provided onto said receiving layer provided with said image or onto and/or in said receiving layer provided with said image if said varnish is incapable of rendering said receiving layer transparent; and a cured layer of said lacquer provided on said receiving layer provided with said image and said cured pattern of said varnish, said lacquer having rendered said parts of said receiving layer in contact therewith substantially transparent, wherein said cured pattern of said varnish forms an opaque watermark. In the second embodiment the information carrier comprising: a rigid sheet or web support; an opaque porous receiving layer capable of being rendered substantially transparent by penetration by a varnish, said receiving layer containing a pigment and a binder; an image provided onto and/or in said receiving layer; a cured pattern of said varnish provided in said receiving layer provided with said image; and a cured layer of a lacquer provided onto said receiving layer provided with said image and said cured pattern of said varnish, or onto and/or in said receiving layer provided with said image and said cured pattern of said varnish if said lacquer is incapable of rendering said receiving layer transparent, said varnish having rendered said parts of said receiving layer in contact therewith substantially transparent, wherein said cured pattern of said lacquer forms a substantially transparent watermark. In the third embodiment the information carrier comprising: a rigid sheet or web support; a transparent porous receiving layer capable of being rendered substantially opaque by penetration by a lacquer, said receiving layer containing a pigment and a binder; an image provided onto and/or in said receiving layer; a cured pattern of a varnish provided onto said receiving layer provided with said image, or onto and/or in said receiving layer provided with said image if said varnish is incapable of rendering said receiving layer opaque; and a cured layer of said lacquer provided on said receiving layer provided with said image and said cured pattern of said varnish, said lacquer having rendered said parts of said receiving layer in contact therewith substantially opaque, wherein said cured pattern of said varnish forms a transparent watermark. In the fourth embodiment the information carrier comprising: a rigid sheet or web support; a transparent porous receiving layer capable of being rendered substantially opaque by penetration by a varnish, said receiving layer containing a pigment and a binder; an image provided onto and/or in said receiving layer; a cured pattern of said varnish provided in said receiving layer provided with said image; and a cured layer of a lacquer provided onto said receiving layer provided with said image and said cured pattern of said varnish, or onto and/or in said receiving layer provided with said image and said cured pattern of said varnish if said lacquer is incapable of rendering said receiving layer opaque, said varnish having rendered said parts of said receiving layer in contact therewith substantially opaque, wherein said cured pattern of said lacquer forms a substantially opaque watermark.
GB 1 073 433 discloses the method of forming an image on a porous, opaque layer comprising applying an imaging material in imagewise configuration which is of similar refractive index to the opaque layer and reducing the viscosity of said imaging material so that it flows into the pores to fill the pores of said opaque layer to render said opaque layer clear in said image areas.
U.S. Pat. No. 4,252,601 discloses an information recording kit for making transparencies for projection of information or for making photographic negatives for reproductions comprising an opaque recording material, a writing liquid for recording information on the recording material and means for applying the writing liquid on the opaque recording material in the form of transparent lines wherein said recording material comprises a transparent backing sheet and an opaque layer adhered to one surface of said backing sheet, said opaque layer comprising a finely divided particulate organic styrene resin pigment uniformly distributed throughout a polyvinylidene chloride film-forming resin binder, said writing liquid comprising a solvent for the organic styrene resin pigment, whereby when said writing liquid is applied to said opaque layer according to a pattern of information the opaque layer becomes transparent to visible light according to said pattern.
WO 81/01389A1 discloses a self-supporting microvoid-containing sheet material which is substantially insensitive to marking by the localized application of heat or pressure but which is receptive to ink, pencil, crayon or similar markings and which is adapted to being temporarily or permanently provided with markings by the application of a colorless liquid, comprising in combination: a self-supporting base sheet and, bonded over at least one side of said base sheet, a reflective opaque white to pastel layer comprising particles bonded by a binder, said particles and binder both having a refractive index in the range of 1.3 to 2.2, interconnected microvoids being present throughout said layer, characterized in that the binder:particle volume ratio being in the range of about 1:20 to 2:3, so that the particles are held in pseudo-sintered juxtaposition, the void volume of the layer being in the range of 15-70%, said binder being thermoset, and layer having an image force of at least 200 grams-force.
U.S. Pat. No. 4,499,211 discloses a microporous molded article having an open-cell structure and comprising a thermoplastic material which possesses an inherent latent structural convertibility and includes effective pores of a diameter in the range from about 0.002 to 10 μm, said thermoplastic material comprising at least about 70 percent by weight of a terpolymer which is composed of from about 20 to 80 percent by weight, relative to the total weight of the terpolymer, of copolymerized fluorinated olefin selected from the group consisting of ethylene and propylene, up to about 40 percent by weight, relative to the total weight of the terpolymer, of copolymerized olefin selected from the group consisting of ethylene and propylene, and from about 80 to 20 percent by weight, relative to the total weight of the copolymer, of copolymerized vinyl acetate, with at least 5 percent of the total proportion of acetate groups contained in the copolymer being converted by saponification into OH groups after copolymerization of the specified comonomers to form the terpolymer.
EP-A 0 390 638 discloses a base sheet comprising a layer capable of becoming, in reversible manner, transparent by contact with a liquid, resistant to a marking by localized application of pressure and/or heat, characterized by the fact that it comprises: at least one flexible sheet, at least one layer applied in aqueous form on the flexible sheet and then dried, said sheet being microporous, opaque, and containing at least non-thermoset particles, at least one binder and optionally other additives.
JP 10-157280A discloses a recording material capable of being printed repeatedly by ink jet printing without deteriorating its recording performance even in the case of using many times by incorporating mat or porous surface and a solvent receiving layer which becomes opaque when no solvent exists and transparent when solvent is received.
U.S. Pat. No. 6,364,993 discloses a laminate comprising a substrate having a first substrate surface containing an image thereon and a polymeric film laminated to said first substrate surface overlying said image, said film containing an exposed water activatable opaque layer having a thickness ranging from about 0.6 mil to about 2.0 mil, said opaque layer derived from a coating formulation comprising from about 5 to about 40 wt. % aluminum silicate and from about 60 to about 95 wt. % binder, wherein the binder comprises a mixture of solvent, butyl acetate, ethylene glycol monobutyl ether and propylene glycol.
U.S. Pat. No. 6,723,383 discloses a process for producing a dry image comprising the steps of: (a) applying an opaque coating composition to the surface of a substrate to form an opaque coating on the substrate, wherein the surface is selected from the group consisting of a light-emitting surface, a reflective surface, a glossy surface, a luminescent surface, and a combination thereof; and (b) contacting the coated substrate with a recording liquid, wherein the opaque coating composition includes an opaque coating agent comprising a polymeric polyacid and a polymeric polybase, and wherein the opaque coating contacted with the recording liquid becomes transparent as a result of the contact.
WO 04/052655A1 discloses a multi-layer opaque and matte ink-jet recording medium, suitable for recording images with dye and pigmented inks, which goes through phase change from opaque to transparent and glossy in at least one printed area to reveal the surface of a substrate and thereby provide light-emitting, reflective, glossy, metallic-looking images or to show holographic images, wherein the recording medium comprises a substrate coated with at least two chemically layers comprising: (a) a first transparent ink-receptive layer comprising a polymeric binder and a cross-linker and optionally having a plasticizer and pigment particles such as alumina and silica coated over the substrate, wherein the cross-linker comprises an azetidinium polymer or a salt thereof, and/or a polyfunctional aziridine or a salt thereof, or a polyfunctional oxazoline and metallic salts; and (b) a second ink-receptive layer comprising an opaque or semi-opaque coating composition, wherein the opaque or semi-opaque coating composition is capable of accepting a printed image and thereby becoming semi-transparent or clearly transparent from application of ink-jet printing ink or similar inks, while presenting a light-emitting, reflective, glossy, metallic-looking or holographic or transparent image of high clarity and quality, wherein said first layer is located between said second layer and the substrate in said recording medium and the first and second layer are chemically coupled.
The inventions of EP-A 1 362 710 and EP-A 1 398 175 both disclose a porous opaque ink receiving layer comprising a pigment and a binder, which is capable of being transparentized with a UV-hardenable lacquer. Moreover, the adhesion of the porous opaque ink receiving to the contiguous layer or support is improved upon transparentization with the UV-hardenable lacquer implying diffusion of the UV-hardenable lacquer to the interface with the contiguous layer or support.
There is a need to extend the security possibilities for providing additional security features to the information carriers disclosed in EP-A 1 362 710 and EP-A 1 398 175. There is also the need for the possibility of personalizing the information carrier i.e. incorporating personal details of the information card carrier e.g. an image or other identification.